In a network in which multiple computers each process changes against the state of a shared entity, such as a database table, some mechanism must be employed to ensure that changes made on one computer will be reflected on all others. When a new computer is introduced into the network that needs a copy of the shared entity, there must be a way to load the data onto the new computer. In a static network in which a lock server or locking protocols are used to control the application of changes, the lock server or locking protocols force a quiescence period long enough for the data to be copied to the new computer.
Consider the analogy of a meeting in which one participant is late. The meeting halts until the late person can be brought up to date.
However, in a dynamic network that requires that changes to the network configuration be made without impacting the processing of the computers already in the network, there needs to be a mechanism to copy the shared entity onto the new computer while changes are being made to the table on other computers. In addition, all those changes must be factored into the entity on the new computer before the computer is brought online.